<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			div:first-child{
				font-style: italic;
			}
			div:first-child+div{
				font-weight: 700;
			}
			div:nth-child(3){
				font-size: 50px;
			}
			.d4{
				font-family: "microsoft yahei";
			}
			div:nth-child(5){  /* 尽量不使用last-child*/
				font:italic bold 50px "宋体";
			}
		</style>
	</head>
	<body>
		<div>123</div>
		<div>1234</div>
		<div>12345</div>
		<div class="d4">123456</div>
		<div>12</div>
	</body>
</html>
